diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index e6dd1f5..08288a1 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -42,6 +42,7 @@ IMAGE_QUALITY_REGEXES = [
     { 'better': NO_TONE_REGEX, 'worse': TONE_REGEX },
     { 'better': COLOR_REGEX, 'worse': MONOCHROME_REGEX },
 ]
+IMAGE_RESOLUTION_REGEX = re.compile('^(?P<x>[0-9]+)x(?P<y>[0-9]+)$')
 
 LANGUAGE_REGEXES = {
     'en_US': re.compile('english|英語', re.I),
@@ -442,21 +443,24 @@ class Collator:
             return select_language
 
         dirs = [src for src in srcs if src.is_dir()]
-        if len(dirs) == 2:
+        non_dirs = [src for src in srcs if not src.is_dir()]
+        if len(dirs) == 2 and len(descendant_files_ignore(dirs[0], self.exclude)) == len(descendant_files_ignore(dirs[1], self.exclude)):
+            resolution_matches = [IMAGE_RESOLUTION_REGEX.match(nname(src)) for src in dirs]
+            if all(resolution_matches):
+                pairs = [(int(m.group('x')), int(m.group('y'))) for m in resolution_matches]
+                for i in range(2):
+                    if pairs[i][0] > pairs[1-i][0] and pairs[i][1] > pairs[1-i][1]:
+                        return self.collate_from_paths([dirs[i]] + non_dirs)
             for quality in IMAGE_QUALITY_REGEXES:
                 def a_not_b(a, b, src):
                     if a in quality:
                         return quality[a].search(nname(src))
                     else:
                         return not quality[b].search(nname(src))
-                better_srcs = [src for src in dirs if a_not_b('better', 'worse', src)]
-                worse_srcs = [src for src in dirs if a_not_b('worse', 'better', src)]
-                if len(better_srcs) == 1 and len(worse_srcs) == 1 and better_srcs[0] != worse_srcs[0]:
-                    better = better_srcs[0]
-                    worse = worse_srcs[0]
-                    if len(descendant_files_ignore(better, self.exclude)) == len(descendant_files_ignore(worse, self.exclude)):
-                        non_dirs = [src for src in srcs if not src.is_dir()]
-                        return self.collate_from_paths([better] + non_dirs)
+                better_dirs = [src for src in dirs if a_not_b('better', 'worse', src)]
+                worse_dirs = [src for src in dirs if a_not_b('worse', 'better', src)]
+                if len(better_dirs) == 1 and len(worse_dirs) == 1 and better_dirs[0] != worse_dirs[0]:
+                    return self.collate_from_paths(better_dirs + non_dirs)
 
         images_vs_pdf = self.try_collate_images_vs_pdf(srcs)
         if images_vs_pdf is not False: